The present invention relates to compounds which are useful for treating or preventing prostaglandin mediated diseases, methods of treatment and pharmaceutical compositions containing such compounds. The compounds are structurally different from conventional NSAIDs and opiates, and are antagonists of the pain and inflammatory effects of E-type prostaglandins.
Two review articles describe the characterization and therapeutic relevance of the prostanoid receptors as well as the most commonly used selective agonists and antagonists: Eicosanoids: From Biotechnology to Therapeutic Applications, Folco, Samuelsson, Maclouf, and Velo eds, Plenum Press, New York, 1996, chap. 14, 137-154 and Journal of Lipid Mediators and Cell Signalling, 1996, 14, 83-87. An article from The British Journal of Pharmacology (1994, 112, 735-740) suggests that Prostaglandin E.sub.2 (PGE.sub.2) exerts allodynia through the EP.sub.1 receptor subtype and hyperalgesia through EP.sub.2 and EP.sub.3 receptors in the mouse spinal cord.
Thus, selective prostaglandin ligands, agonists or antagonists, depending on which prostaglandin E receptor subtype is being considered, have anti-inflammatory, antipyretic and analgesic properties, and in addition inhibit hormone-induced uterine contractions. Moreover, the compounds have anti-cancer effects.
The compounds have a reduced potential for gastrointestinal toxicity, a reduced potential for renal side effects, a reduced effect on bleeding times and a lessened ability to induce asthma attacks in aspirin-sensitive asthmatic subjects.